flywheel bolt came loose
 

so, what do people do to prevent this? Locktight? More torque? Something else? Is the flywheel bolt coming loose possibly indicitive of another problem that causes abnormal amounts of vibration?

and by bolt i mean nut...my bad

Loctite..

Is there some sort of symptom that comes along with the nut coming loose, cause I'm envisioning it coming off and then everything exploding.

if the motor was rebuilt it could just be that who ever torqued the nut did not reach the required 290-361 ft pounds and or did not use thread sealant thread lock.

symptoms are a terrible rattling noise at low rpms (especially in neutral). It seems that at higher rpms the flywheel balances itself. With clutch pedal depressed, it generally stops the rattling.

sounds like you are describing a bad throw out bearing

throw out bearing would make the noise when the clutch is depressed, not the opposite. Besides i already dropped the tranny and i was able to remove the flywheel nut by hand!

Loctite on the threads and silicone on the end.